Receiving units of this type are known (DE 10 2004 056 439 A1). They are used especially in magnetic levitation trains for the contactless, inductive transmission of electric power from a track to a vehicle. At least one primary conductor, which is designed as a transmitting coil and is connected to a power source, is provided for this purpose at the track and at least one secondary receiver coil is provided at the vehicle. This coil is preferably designed as part of a receiving unit and is fastened with this to a magnetic back box, which has the carrier magnets and is in turn connected to an undercarriage or body of the vehicle via frame straps.
To improve the magnetic coupling between the primary conductor and the receiver coil and to avoid eddy current losses, the receiver coil is provided with means for concentrating the lines of magnetic flux generated by the primary conductor on its side facing away from the primary conductor. These means contain flux-conducting elements in the form of strips and connection elements, which connect the ends thereof and consist of a material having high permeability and high electrical resistance, preferably a ferrite, especially a soft ferrite. The strips and connection elements are connected into a grid frame to be placed on the receiver coil by bonding or according to another method.
Flux-conducting elements are manufactured from a material such as ferrite or the like by pressing and subsequent sintering of a powder prepared from this material. The flux-conducting elements obtained as a result are comparatively brittle, mechanically delicate and are poorly processable. In addition, the joining together of the flux-conducting elements into a grid frame is very labor-intensive.